An air-standard Diesel cycle has a compression ratio of 16 and a cutoff ratio of 2. At the beginning of the compression process, air is at 99 kPa and 27°C. Account for the variation of specific heats with temperature. The gas constant of air is R = 0.287 kJ/kg.K.

Q1.5 (v6q9-52, Diesel) An ideal cycle has a compression ratio of 18 and a cutoff ratio of 1.5. Determine the maximum air temperature and the rate of heat addition to this cycle when it produces 200 hp of power; the cycle is repeated 1200 times per minute; and the state of the air at the beginning of the compression is 95kPa and 17C. Use constant specific heats at room temperature. Ans 1382K, 227.2kW

Consider a Diesel cycle with cold-air-standard assumptions, and compression ratio of 21. The temperature and pressure at the beginning of the compression process are 320K and 120kPa respectively. The cutoff ratio for this cycle is 1.8. The isentropic efficiency of the compression and expansion process are 85%. Determine the temperature and pressure at the end of each process of the cycle, the heat transfer per unit mass in and out of the air; qin and qout, thermal efficiency of the cycle, and the mean effective pressure of the cycle.

A 4 stroke spark ignition engine operates on an ideal Otto cycle with a compression ratio of 8.5. This engine compresses the fresh air-fuel mixture from its initial volume to a final volume of 75cm. The air is at 101kPa and 20°C prior to the compression stroke. Temperature at the end of isentropic expansion is 750K. Make air standard assumption to solve this problem. Air properties: cp = 1.005KJ/kg.K; cy = 0.718KJ/kg.K; R = 0.287KJ/kg.K. Determine, • Mass of air in the engine (in kg). (answer to 4 decimals) (Hint: treat air as ideal gas at start of intake stroke - point 1 on P-V diagram) Isentropic Isentropic * Iout BDC TDC